120 The Food of Birds. 



the commencement of the autumnal multiplication of this 

 order which will be found reflected to a very notable de- 

 gree in the food of the bluebird further on. Only traces 

 ef spiders and thousand-legs were discovered. Fifty-four 

 parts of fruit were eaten, sixteen of which were wild. 

 Nearly all of the garden fruits were blackberries, — cherries 

 constituting but three per cent, of the food for the month. 



Septemher. 



The catbird leaves our latitude in September, and only 

 six specimens were secured, — all of them on or before the 

 ITtli, in the vicinity of Normal and Bloomington. The 

 chief peculiarity of the food of the month is the substitu- 

 tion of cherries and wild fruits for blackberries. Seventy- 

 six per cent, of the food at this time consisted of fruits, 

 all wild but the grapes, which amounted to fourteen per 

 cent. Elderberries, wild cherries and the fruit of the Vir- 

 ginia creeper were the most important elements. Carniv- 

 orous thousand-legs amounted to three per cent, of the 

 food and insects proper to twenty-one per cent., nearly 

 half of which were ants. But few caterpillars had been 

 eaten by these birds, and only seven per cent, of Coleop- 

 tera, — five per cent, being Harpalidae. The lower orders 

 of insects were conspicuous only by their absence. 



We are now prepared for the review of the general av- 

 erages of the season, and the indications which these afford 

 of the economic value of the catbird. Taking the rec- 

 ord of the year together as found in the vertical column 

 at the right of the table on pages 125, 126, 127, the seventy 

 birds of the species examined are found to have eaten for- 

 ty-three parts of insects, two parts of spiders and harvest- 

 men, three parts of thousand-legs and fifty-two parts of 

 fruits. Only thirty-three per cent, of the food consisted 

 of tame fruits, four per cent, being raspberries, twenty 

 per cent, blackberries, one per cent, currants, four per 

 cent, tame cherries, one per cent, strawberries and three 

 per cent grapes. Scrutinizing more closely the details of 

 the insect food, we find that ants form twelve per cent, of 

 the total for the season ; Diptera, chiefly crane-flies, about 

 five per cent. ; Lepidoptera six per cent. ; and beetles 



